1. Field of the Invention
The present invention relates to an image processing apparatus for supporting diagnosis which is performed based on an image of an anterior ocular segment. Specifically, the present invention relates to an anterior ocular segment tomographic image analysis method and an anterior ocular segment tomographic image analysis apparatus to be used for performing diagnosis based on an acquired anterior ocular segment tomographic image.
2. Description of the Related Art
An optical coherence tomographic image acquiring apparatus for eyes, such as optical coherence tomography (OCT), is capable of three-dimensional observation of an internal state of a retina layer and a state of cornea of an anterior ocular segment. This optical coherence tomographic image acquiring apparatus has been receiving attention in recent years because the optical coherence tomographic image acquiring apparatus is useful for accurate diagnosis of a disease.
Japanese Patent Application Laid-Open No. 2011-147611 discloses a unit for easily determining multiple parameters for measuring an opening degree of a chamber angle based on an anterior ocular segment tomographic image, which includes a chamber angle region of an eye to be inspected and is obtained by the OCT, by causing an examiner to perform respective input operations through use of a graphic display while viewing the anterior ocular segment tomographic image displayed on a monitor. In this case, the examiner extends and turns an auxiliary line positioned on an anterior surface of an iris of an anterior ocular segment in the tomographic image and associates the auxiliary line with the tomographic image, thereby deducing a position of an angle recess even in the case where it is difficult to view the vicinity of the angle recess to determine the above-mentioned parameters.
By the way, in the case where an eye to be inspected has a symptom of narrow angle eye, the shape of an anterior surface of an iris of an anterior ocular segment is curved in some cases. In this case, with the procedure disclosed by Japanese Patent Application Laid-Open No. 2011-147611, there is a risk in that a region including the anterior surface of the iris of the anterior ocular segment as one side, which is to be required for calculating an opening degree of a chamber angle, may not be determined accurately. Specifically, in the case of the method disclosed by Japanese Patent Application Laid-Open No. 2011-147611, the anterior surface of the iris of the anterior ocular segment is approximated with a straight line, and hence, an opening degree of a chamber angle may be calculated as a value larger than a usual value. In this case, there is a risk in that a disease such as narrow angle eye that is required to be treated may be overlooked.